Australian Hannah Green has won the women's LPGA Championship at Hazeltine.

The 22-year-old from Perth shot a 72 on Sunday for a nine-under total of 207 to win by one shot from defending champion Sung Hyun Park (68) of South Korea.

It was Green's first victory on the LPGA Tour and she becomes the first Australian woman since Karrie Webb (Kraft Nabisco 2006) to win a major. She is the first Australian major winner since Jason Day at the men's PGA Championship in 2015.

“She was made for winning LPGA tournaments and major championships,” Webb said of Green after her breakthrough victory.

Green emotional after 'surreal' major win

Hannah Green poses with the LPGA trophy and the Australian flag. (PA AAP)

Green held her nerve and saved par from the bunker with a five-foot putt on the final hole after Park drained an 18-foot birdie putt on the 18th hole to bring added pressure.

Among those who celebrated with Green was Webb, who brought Green to America four years ago as part of her scholarship program.

Green, in only her second full year on the LPGA Tour, is the first wire-to-wire winner of this major since 2011.

Hannah Green drives during the final round of the LPGA Championship. (PA AAP)

"I'm pretty much speechless," said Green. "I was really nervous the last five holes and just really - I made a clutch putt and that was kind of got me through another one.